Abstract: An implantable medical device (“IMD”) is provided having an antenna and an RF telemetry module for far field telemetry communications arranged on an exterior of the IMD housing, such that telemetry signal processing may be performed on the exterior of the housing. One or more feedthrough conductive paths extend through the housing to communicatively couple the RF module to circuitry within the housing. In this manner RF module is arranged entirely external to the housing, such that only power and/or low frequency data bit signals are required to be passed through the feedthrough conductive path. This allows the feedthrough conductive path to be filtered to prevent undesired interference signals (e.g., electromagnetic interference (EMI) signals) from entering the housing through the feedthrough conductive path coupled to the RF module. In some embodiments, the antenna and RF module are formed in an integrated assembly attachable to an exterior portion of the housing.

Abstract: An implantable medical device with a medical module, an antenna, a transceiver and an impedance match circuit. The transceiver is operatively coupled to the antenna and the medical module and facilitates wireless transmission of data between the medical module and an external device. The impedance match circuit is operatively coupled between the transceiver and the antenna and has a plurality of predetermined selectable configurations, each providing a particular impedance matching characteristic.

Abstract: A low power multiple channel receiver mixing architecture for detecting wake-up signals over multiple communication channels in sniff processing performed in an implantable medical device (IMD). The architecture includes a direct conversion real receiver configured to scan a selected center channel and a Weaver receiver configured in parallel to the direct conversion real receiver to simultaneously scan side channels, together simultaneously detecting whether a wake-up signal is being received over the center and side channels with minimal power consumption. The architecture further utilizes a falsing protection algorithm that reduces power consumption during sniff operations by inhibiting the sniffing of channels likely to provide a false indication of a wake-up signal based the presence of unwanted signals on those channels.

Abstract: An implantable medical device (“IMD”) is provided having an antenna and an RF telemetry module for far field telemetry communications arranged on an exterior of the IMD housing, such that telemetry signal processing may be performed on the exterior of the housing. One or more feedthrough conductive paths extend through the housing to communicatively couple the RF module to circuitry within the housing. In this manner RF module is arranged entirely external to the housing, such that only power and/or low frequency data bit signals are required to be passed through the feedthrough conductive path. This allows the feedthrough conductive path to be filtered to prevent undesired interference signals (e.g., electromagnetic interference (EMI) signals) from entering the housing through the feedthrough conductive path coupled to the RF module. In some embodiments, the antenna and RF module are formed in an integrated assembly attachable to an exterior portion of the housing.

Abstract: An antenna for an implantable medical device (IMD) is provided including a monolithic structure derived from a plurality of discrete dielectric layers having an antenna embedded within the monolithic structure. Superstrate dielectric layers formed above the antenna may provide improved matching gradient with the surrounding environment to mitigate energy reflection effects. A outermost biocompatible layer is positioned over the superstrates as an interface with the surrounding environment. A shielding layer is positioned under the antenna to provide electromagnetic shielding for the IMD circuitry. Substrate dielectric layers formed below the antenna may possess higher dielectric values to allow the distance between the antenna and ground shielding layer to be minimized. An electromagnetic bandgap layer may be positioned between the antenna and the shielding layer.

Abstract: An implantable medical device with a medical module, an antenna, a transceiver and an impedance match circuit. The transceiver is operatively coupled to the antenna and the medical module and facilitates wireless transmission of data between the medical module and an external device. The impedance match circuit is operatively coupled between the transceiver and the antenna and has a plurality of predetermined selectable configurations, each providing a particular impedance matching characteristic.

Abstract: A low power multiple channel receiver mixing architecture for detecting wake-up signals over multiple communication channles in sniff processing performed in an implantable medical device (IMD). The architecture includes a direct conversion real receiver configured to scan a selected center channel and a Weaver receiver configured in parallel to the direct conversion real receiver to simultaneously scan side channels, together simultaneously detecting whether a wake-up signal is being received over the center and side channels with minimal power consumption. The architecture further utilizes a falsing protection algorithm that reduces power consumption during sniff operations by inhibiting the sniffing of channels likely to provide a false indication of a wake-up signal based the presence of unwanted signals on those channels.

Abstract: A compensation circuit is disclosed for compensating bias levels of an operational circuit in response to variations in a supply voltage. The compensation mechanism identifies variations in the supply voltage by comparing the voltage of a selected node of the operation circuit with a relatively constant or fixed reference voltage. Based on the results of the comparison, the compensation mechanism adjusts selected bias levels in the operational circuit, preferably using current stealing circuitry, so that the functionality and performance of the operational circuit can be substantially maintained. A biasing circuit for biasing one or more differential pairs is also disclosed.

Abstract: A circuit in accordance with the invention comprises a differential amplifier; and a direct current (DC) source coupled with the differential amplifier. The DC source generates a direct current that is communicated in substantially predetermined portions to multiple inverting input terminals of the differential amplifier. The direct current is applied so as to shift a common-mode voltage of electrical signals that are processed by the differential amplifier. The shift in the common-mode voltage is proportional to the direct current generated by the DC source.

Abstract: A circuit in accordance with the invention comprises a differential amplifier; and a direct current (DC) source coupled with the differential amplifier. The DC source generates a direct current that is communicated in substantially predetermined portions to multiple inverting input terminals of the differential amplifier. The direct current is applied so as to shift a common-mode voltage of electrical signals that are processed by the differential amplifier. The shift in the common-mode voltage is proportional to the direct current generated by the DC source.

Abstract: A compensation circuit is disclosed for compensating bias levels of an operational circuit in response to variations in a supply voltage. The compensation mechanism identifies variations in the supply voltage by comparing the voltage of a selected node of the operation circuit with a relatively constant or fixed reference voltage. Based on the results of the comparison, the compensation mechanism adjusts selected bias levels in the operational circuit, preferably using current stealing circuitry, so that the functionality and performance of the operational circuit can be substantially maintained. A biasing circuit for biasing one or more differential pairs is also disclosed.

Abstract: A programmable output buffer with independently controllable current mirror legs is disclosed. The output buffer includes a current mirror that has a reference leg and a number of current mirror legs. The reference leg is biased using a reference current that is relatively independent of the supply voltage. Each of the current mirror legs is coupled to the output terminal of the output buffer, and conducts a current that is proportional to the reference current. This produces an output current that is relatively independent of variations in the supply voltage. To provide a programmable output power level, each of the current mirror legs are separately enabled. By controlling which of the current mirror legs are enabled, the output power of the output buffer can be controlled.